PEAK-HOLD CIRCUIT

PROBLEM TO BE SOLVED: To provide a peak-hold circuit that can acquire a peak of a small amplitude signal.SOLUTION: The peak-hold circuit includes: a switch Mn1 configured to be turned on when an output voltage Vis increased and be turned off when Vis held; a capacitor C1 for storing a charge when Vis increased and holding the stored charge when Vis held; a reset switch RSW for releasing the charge stored in the C1 back to an initial state in accordance with a reset signal RST; a voltage comparator 1 for receiving an input of V, and outputting a voltage to turn the Mn1 on when Vis equal to or higher than a reference voltage Vand outputting a voltage to turn the Mn1 off when Vis lower than the reference voltage; and an output-to-negative-power-supply voltage attenuation circuit 2 for attenuating Vbefore output to the reference of the voltage comparator.